Couple of questions for those using oval chainrings.

If you swap between a bike with an oval chainring, and other bikes without, does it mess with your pedal stroke?

Does it create more bob when used on a full suss?

When swapping, you get used to the feel of the ‘new’ style within about ten minutes.

Generally less bob, ask Brant.

MSP – Member
If you swap between a bike with an oval chainring, and other bikes without, does it mess with your pedal stroke?

Not in my experience.

Does it create more bob when used on a full suss?

If anything, less.

Generally less bob, ask Brant.

You could orientate them to create more bob if you wanted.

I actually can’t tell, on mine. It’s a hardtail so it’d be working pretty hard to create bob, to be fair. But pedalling, it really just feels the same to me. Not sure if it’s easier to pedal or not but that’s the sort of thing that’s hard to identify.

Haven’t found any downsides, haven’t ruled out benefits, is basically where I am just now.

My experience, I quite often switch between bikes with oval and non-oval. I don’t notice any difference when pedalling (though am convinced they are less fatiguing over the course of a ride.)

Never tried one on a FS.

I’ve one on my SS at the moment – which is about to get a power meter attached to it for testing for a few months.

I’ll do some testing with wonky and non-wonked rings. SS, geared HT, geared full sus.

May as well use some of the skills my PhD gave me :/

There are possibly some issues with power meters and oval rings.

I don’t buy that there is any power difference between a round or oval ring. It is all irrelevant anyway- just do another 20 minute test with the oval ring and use that new FTP to scale efforts. Speed is about more than just power too so it gets incredibly complicated to gauge if one ring or the other generates real world speed differences.

I guess you could do such a test on a turbo and collect the power and wheel speed data. Would make an interesting comparison. I’d probably go for a longer test too given that it may be helping to reduce fatigue. Think it would be interesting to test at different cadences and powers too, given that by spending less time in the “dead spot” it could be beneficial in high resistance and low cadence scenario.

I’ve got a spider (P2M) and a hub (PowerTap) based PM. PowerTap, being hub based, is meant to be accurate with oval or round rings. P2M, being spider based, is meant to be out. If I had the time I’d do a few tests back to back with both PM fitted and compare the difference.

My experience, I quite often switch between bikes with oval and non-oval. I don’t notice any difference when pedalling (though am convinced they are less fatiguing over the course of a ride.)

… having said that, one thing I do notice with the rotor rings is a change in orientation of the ring mounting. Comes with 5 pre-defined positions. If I go from, say, position 2 to position 3, the difference is noticeable.

For me, they’ve never been about speed. Their biggest advantage is power control when climbing – much less of a dead spot. That said, my granny ring used to be at 40% eccentricity (24t varying between 20t and 28t equivalent) 😯

I guess you could do such a test on a turbo and collect the power and wheel speed data. Would make an interesting comparison.

I did this over 50x Z3 intervals (just out of curiosity) taken before and after changing the rings and couldn’t detect any trend differences between the rings. There is probably a worse relationship between turbo wheel speed and power to be honest which adds more uncertainty than there are differences between the rings! You can see this when you look at virtual power from Trainerroad and real Power- wheels speed is smoother than power due to flywheel effects I guess and wheel speed/ VP overestimates the power as the troughs aren’t measured to the same extent.

I think any test you might want to do has more uncertainty in the test than there is difference between the rings which leads me to be in the same place as Northwind

Haven’t found any downsides, haven’t ruled out benefits, is basically where I am just now.

I’ve got an absolute black oval narrow/wide 30/34 on a full sus (lapierre zesty)
After the first few hours of “feeling weird” I really like it, genuine improvement on low speed/technical climbing.
And no noticeable bob.